Potentiometer.



H.v GBRNSBACK.

POTENTIOMETER.

APPLIOATION FILED 111:0.'1, 1910.

Patented Apr. 4, 1911.

UNITED STATES PATENT OFFICE.

HUGO GERNSBACK, F YORK, N. Y.

POTENTIOMETEB.

Specication of Letters Patent.

1 ate1rmer1y Apr-4. 1911'.

Application led December 7, 1910. Serial No. 596,068.

4ments in Potentiometers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the artto'which it appertains to make and use the same, reference being had to the accompanying drawings, and to the lettersand figures of reference marked thereon, which form a part of this specification.

This invention relates-v to potentiometers and to that class used in Wireless telegraphy, having for its object to provide a simple and compact device to control 'and regulate the resistance in electrical circuits.

Other objects will be apparent from the following specification, appended claim and drawings thereof, in which Figure 1 is af plan view of the device. Fig. 2 is a bottom View thereof. Fig. 3 is a vertical central sectional view through Fig. 1. -Fig. 4 is a diagrammatic view showing the application of the device; v

Referring more particularly to 'the drawings, there is shown a base 1 Lmade of gut-tapercha or the'like-and having a circular shape, and on vthis base lis the graduated scale 2. The under face of thev base is dished as (at 3 and in said face is cut a cove 4 which maybe described as formmgvthree sides of a square, in which groove is placed the high electrical resisting materral, such as bars of graphite 5 and 6. Said bars are embedded in the under face andare so arranged that the ends of the top bar 5 extend into thepath of the side bars 6 and receive the pressure exerted on bars 6 by resilient'tongues l7 of the 'washers 8 .forming -part of thebinding postsv 9v of which there are two, one at the lower end of each side bar 6, and said binding posts terminate above the baseto, receive the wires from the batteryl and instrument as shown in Fig. 4. Mounted between the binding posts 9 is a third-one 10 which is electrically connected with a bar 11 -which in turn contacts'` with the'central screw 12. This screw 1.2 Vcarries a' mbv'ablecontactl which bears in which A indicates the aerial, VC, the

variable condenser, TC the tuning coil, D the detector, G ground, C condenser, TR the telegraph receiver, B the battery and P the potentiometer, the wiring in which gure is of the usual construction in wireless telegraph.

The operation ofthe/ device is obvious from the'diagram o f Fig.'4, that by pro er connection with the circuits of the wire ess system 'and battery, any potential may be .caused to pass through the receiver by simply turnin the thumb piece.

It is evi ent that the device is applicable inan electrical circuit as a rheostat by using the middle binding post and either of the side ones and, by the rotation of the pointer, the circuit may embody the entire length of lthe high electrical resisting bars orlit may be varied until the current passes through the pointer, resilient arm vand through the binding post.

What I claim to be new is i v A potentiometer, comprisin a base having a dished under face, bin ing osts -on `said base, a scale indicated on'said) base, a sleeve embedded in the center of said base, a screw passinl through said sleeve, a'thumb piece and in icator on one end, a contact on `the other end of said screw, electrical connections between said screw and one of said 'of the base, bars of high electrical kresisting adapted to contact with the contact int on tween the ends of said bars of high resisting materials and the other binding posten' In Atestimon whereof I hereuntoaix my signature in t e presence of twor witnesses. HUGO GERNSBACK. Witnesses: l'

' E. D. .IUN1o1z,` E. R. WaADoN.

binding posts, a groovein'the bottom face y qualities embedded in said grooves, said bars said screw, andelectrical connections be- 

